Slim fan

ABSTRACT

A slim fan includes a casing, a fan module and a ring cover. The casing includes an upper casing which has an opening, and a lower casing. The fan module includes a plurality of fans annularly disposed in the opening, and each of the fans has a first side and a second side opposite to each other. The ring cover is connected to the first side of the fans and exposed out of the opening. The height of the fans is equal to that between the upper casing and the lower casing.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefits of U.S. provisional application Ser. No. 61/619,402, filed on Apr. 2, 2012. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a slim fan and, more particularly, to a slim fan with better efficiency.

2. Description of the Related Art

Nowadays, various portable electronic devices, such as a notebook personal computer (Notebook PC), a mobile phone, a personal digital assistant (PDA), a handheld computer or a tablet computer, are widely used to meet requirements of high speed, high efficiency, light, thin and small. Taking the notebook computer as an example, since the notebook computer cannot provide much space to accommodate a heat dissipating system, it is important to improve the heat dissipating efficiency in the limited space.

The notebook computer usually includes a fan to dissipate heat from the components inside the notebook computer. When the fan operates, hot air enters a casing of the fan via an inlet, and is blown out of the computer via an outlet to decrease the temperature inside the notebook computer.

The conventional fan includes a motor, a fan module, an upper casing and a lower casing. Since the fan module is disposed between the upper casing and the lower casing, the height of the fan module should be lower than the height of the casing to reserve space for allowing the fan module to deflect in rotating, so as to avoid friction with the casing. Generally, a gap of 0.5 mm to 1.5 mm should be reserved between the fan module and the casing. The height of the fan is about 4 mm to 5 mm, and thus the gap between the fan module and the casing occupies 30% to 45% of the space therebetween. Moreover, air quantity and air pressure are in proportion to the height of the fan module. Consequently, when the fan is thinner, the height of the fan module is decreased, and the performance of the fan is affected.

BRIEF SUMMARY OF THE INVENTION

A slim fan including a casing, a fan module and a ring cover is provided. The casing includes an upper casing and a lower casing, and the upper casing has an opening. The fan module includes a plurality of fans, the fans are annularly disposed in the opening, and each of the fans has a first side and a second side opposite to each other. The ring cover is connected to the first side of the fans, and the ring cover is exposed out of the opening Height of each of the fans equals to that between the upper casing and the lower casing.

In sum, the fan module and the ring cover of the slim fan are exposed out of the casing and rotate relative to the casing. Comparing to the conventional fan module disposed in the casing in limited space so as to reserve space for the deflecting of the fan module, the height of the slim fan in embodiments equals to the height between the upper casing and the lower casing, which improves the efficiency of the fan. Furthermore, a first leakproof part with a cambered or an inclined plane can be disposed at the ring cover, or second leakproof parts are extended from the upper casing and the lower casing towards each other to guide the air inwards, make the air flow through the outlet of the casing and prevent the air being leaked out of the gap between the ring cover and the casing, so as to increase the air quantity and the air pressure. A leakproof film may also be fixed on the casing or the ring cover to cover the gap and block the air being leaked out of the casing or the ring cover.

These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic diagram showing a slim fan in a first embodiment;

FIG. 1B is a schematic diagram showing a fan module and a ring cover of the slim fan in FIG. 1A;

FIG. 1C is a side view of the slim fan in FIG. 1A;

FIG. 1D is a rear view of the slim fan in FIG. 1A;

FIG. 1E is a sectional schematic diagram showing the slim fan in FIG. 1A;

FIG. 2 is a partial schematic diagram showing a slim fan in a second embodiment;

FIG. 3A is a schematic diagram showing a slim fan in a third embodiment;

FIG. 3B is a sectional schematic diagram showing the slim fan in FIG. 3A; and

FIG. 4 is a sectional schematic diagram showing a slim fan in a fourth embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1A is a schematic diagram showing a slim fan in a first embodiment. FIG. 1B is a schematic diagram showing a fan module and a ring cover of the slim fan in FIG. 1A. FIG. 1C is a side view of the slim fan in FIG. 1A. Please refer to FIG. 1A to FIG. 1 C, a slim fan 100 in the first embodiment includes a casing 110, a motor 120, a fan module 130 and a ring cover 140.

The casing 110 includes an upper casing 112 and a lower casing 114, and the upper casing 112 has an opening 118. The fan module 130 includes a plurality of fans 136, the fans 136 are annularly disposed in the opening 118, and each of the fans 136 has a first side 136 a and a second side 136 b. The ring cover 140 is connected to the first side 136 a of the fans 136 and exposed out of the opening 118. The height of each of the fans 136 equals to that between the upper casing 112 and the lower casing 114. Thus, in the embodiment, each of the fans 136 has a same height.

The motor 120 is disposed in the casing 110 and inside the fan module 130. In the embodiment, the slim fan 100 includes two ring covers 140, which is not limited herein. The two ring covers 140 are respectively connected to the first side 136 a and the second side 136 b of the fans 136.

In the embodiment, the fan module 130 and the two ring covers 140 are integratedly formed by plastic or metal injection molding. In other embodiment, the fans 136 and one of the ring covers 140 may be formed first by plastic or metal injection molding, and if the ring cover 140 is fixed at the first side 136 a of the fans 136, the other ring cover 140 is fixed at the second side 136 b of the fans 136 by hot melt, ultrasonic wave or gluing after it is injected. The fan module 130 and the two ring covers 140 may also be formed respectively by plastic or metal injection molding, and then they are combined together. The fan module 130 and the ring covers 140 may be fixed by hot melt, welding, screws, gluing or locking, which is not limited herein.

As shown in FIG. 1B, the fan module 130 further includes a hub 134, the fans 136 are disposed around the hub 134. As shown in FIG. 1C, the height of the hub 134 and the fans 136 (which means the height of the fan module 130) equals to the height between the upper casing 112 and the lower casing 114.

In the embodiment, the fan module 130 and the ring cover 140 are exposed out of the casing 110 and rotate relative to the casing 110. Comparing to the conventional fan module in the casing, the fan module 130 and the ring cover 140 are exposed out of the casing 110. When the slim fan operates, the casing 110 keeps still, and the fan module 130 and the ring cover 140 rotate relative to the casing 110. Since the fan module 130 is not covered by the casing 110, it does not need to reserve space for the fan module 130 to deflect along a rotating axis, and the height of the fan module 130 can be equal to the height of the casing 110. Thus, the height for the fans 136 is increased, and the performance of the slim fan 100 is greatly improved in limited space.

FIG. 1D is a rear view of the slim fan in FIG. 1A. Please refer to FIG. 1D, in the embodiment, the casing 110 further includes a fastening cover 116, and the lower casing 114 includes a hole 114 a. The fastening cover 116 covers the hole 114 a and is connected to the lower casing 114, the motor 120 is disposed on the fastening cover 116, and a part of the fan module 130 is exposed out of the hole 114 a, which is not limited herein.

FIG. 1E is a sectional schematic diagram showing the slim fan in FIG. 1A. In FIG. 1E, the air enters the fan module 130 from the first side 136 a and the second side 136 b of the fans 136, and then flows out via an outlet 117 of the casing 110. Since the fan module 130 and the ring cover 140 can rotate relative to the casing 110, a gap D exists between the fan module 130, the ring cover 140 and side of the casing 110. In order to avoid the air being leaked out from the gap D to affect the air quantity and the air pressure of the outlet 117, a first leakproof part 142 is extended from the ring cover 140 towards the fans 136, as shown in FIG. 1E. The first leakproof part 142 includes a curved surface to make the air concentrate inwardly. Thus, the air does not be leaked out and the air quantity and the air pressure of the slim fan 100 are improved easily.

The first leakproof part 142 also may be an inclined plane, as long as it can guide the air inwards and make the air flow to the outlet 117, which is not limited. Moreover, as shown in FIG. 1A, since the gap D between the ring cover 140 and the casing 110 is annular, the first leakproof part 142 of the ring cover 140 is also annular, so as to ensure that the air in all directions is gathered and guided to the outlet 117 by the contour of the casing 110.

FIG. 2 is a partial schematic diagram showing a slim fan in a second embodiment. As shown in FIG. 2, inner space 219 is between the upper casing 212 and the lower casing 214 and connected to the opening 218. The difference between the slim fan in FIG. 2 and in FIG. 1E is that two second leakproof parts 212 a and 214 a in FIG. 2 are extended from the positions of the upper casing 212 and the lower casing 214 near the ring cover 240, respectively, and extended towards the inner space 219, to prevent the air from being leaked out of the gap D between the ring cover 240 and the casing 210. That means, the two second leakproof parts 212 a and 214 a are on the upper casing 212 and the lower casing 214 and at the position near the ring cover 240, and they are extended towards each other.

When the air flows from the fan module 230 towards the casing 210, the second leakproof parts 212 a and 214 a guide the air inwards and prevent it from being leaked out of the gap D between the ring cover 240 and the casing 210. Additionally, the second leakproof parts 212 a and 214 a are annular to ensure the air in all directions is gathered and guided to the outlet 217 by the contour of the casing 210.

In another embodiment, the second leakproof part 212 a or the second leakproof part 214 a may be extended from the position of one of the upper casing 212 and the lower casing 214 near the opening 218 and extended towards the inner space 219, and the first leakproof part is extended from the ring cover 240 on the opposite side to prevent the air from being leaked.

FIG. 3A is a schematic diagram showing a slim fan in a third embodiment. FIG. 3B is a sectional schematic diagram showing the slim fan in FIG. 3A. Please refer to FIG. 3A and FIG. 3B, the difference between the slim fan 300 in FIG. 3A and the slim fan 100 in FIG. 1E is that, in FIG. 3A, the slim fan 300 further includes a leakproof film 350 fixed on the casing 310. The leakproof film 350 covers the gap D between the casing 310 and the ring cover 340 to prevent the air from being leaked.

In the embodiment, the leakproof film 350 is above the gap D between the casing 310 and the ring cover 340, and it does not contact with the ring cover 340. Thus, the leakproof film 350 does not affect the rotation of the fan module 330 and the ring cover 340. When the fan module 330 and the ring cover 340 rotates relative to the casing 310, the air is leaked from the gap D between the ring cover 340 and the casing 310 is blocked by the leakproof film 350, so as to reduce the air leaked quantity from the gap D between the ring cover 340 and the casing 310.

Furthermore, as shown in FIG. 3A, the leakproof film 350 is annular, and the shape of the leakproof film 350 can be various with that of the gap between the casing 310 and the ring cover 340, which is not limited herein. The leakproof film 350 may be fixed at the casing 310 by gluing, welding, screws or locking, which is not limited herein.

FIG. 4 is a sectional schematic diagram showing a slim fan in a fourth embodiment. The difference between the slim fan 400 in FIG. 4 and the slim fan 300 in FIG. 3B is that, the leakproof film 450 of the slim fan 400 in FIG. 4 is fixed on the ring cover 440, and the leakproof film 450 does not contact with the casing 410. Thus, the leakproof film 450 rotates with the ring cover 440 relative to the casing 410. When the fan module 430 and the ring cover 440 rotate relative to the casing 410, the air is leaked from the gap D between the ring cover 440 and the casing 410 is blocked by the leakproof film 450 on the ring cover 440.

In sum, the fan module and the ring cover of the slim fan are exposed out of the casing and rotate relative to the casing. Comparing to the conventional fan module disposed in the casing in limited space so as to reserve space for the deflecting of the fan module, the height of the slim fan in embodiments equals to that between the upper casing and the lower casing, which improves the efficiency of the fan. Furthermore, a first leakproof part with a curved surface or an inclined plane can be disposed at the ring cover, or second leakproof parts are extended from the upper casing and the lower casing towards each other to guide the air inwards, make the air flow through the outlet of the casing and prevent the air from being leaked out of the gap between the ring cover and the casing, so as to increase the air quantity and the air pressure. A leakproof film may also be fixed on the casing or the ring cover to cover the gap and block the air being leaked out of the casing or the ring cover.

Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, the disclosure is not for limiting the scope. Persons having ordinary skill in the art may make various modifications and changes without departing from the scope. Therefore, the scope of the appended claims should not be limited to the description of the preferred embodiments described above. 

What is claimed is:
 1. A slim fan, comprising: a casing including an upper casing and a lower casing, wherein the upper casing has an opening; a fan module including a plurality of fans, wherein the fans are annularly disposed in the opening, and each of the fans has a first side and a second side opposite to each other; and a ring cover connected to the first side of the fans and exposed out of the opening; wherein the height of each of the fans equals to the height between the upper casing and the lower casing.
 2. The slim fan according to claim 1, wherein a first leakproof part is extended from the ring cover towards the fan, and the first leakproof part has a curved surface or an inclined plane.
 3. The slim fan according to claim 2, wherein the first leakproof part is annular.
 4. The slim fan according to claim 1, wherein an inner space is between the upper casing and the lower casing and is connected to the opening, and a second leakproof part is extended from the position of at least one of the upper casing and the lower casing near the ring cover and is extended towards the inner space.
 5. The slim fan according to claim 4, wherein the second leakproof part is annular.
 6. The slim fan according to claim 1, wherein the slim fan further includes a leakproof film fixed on the casing or the ring cover, a gap is formed between the casing and the ring cover, and the leakproof film covers the gap.
 7. The slim fan according to claim 6, wherein the leakproof film is annular.
 8. The slim fan according to claim 1, wherein the fan module further includes a hub, the fans are disposed around the hub, and height of the hub and the fans equals to height between the upper casing and the lower casing.
 9. The slim fan according to claim 1, wherein the casing includes a fastening cover, the lower casing has a hole, the fastening cover covers the hole and bridges over the lower casing, and a part of the fan module is exposed out of the hole.
 10. The slim fan according to claim 1, wherein the fan module and the ring cover are integratedly formed. 